Three weeks ago, the Sharks and the Chicago Blackhawks were among the NHL’s surging teams. They looked like two franchises perfectly capable of once again meeting deep in the postseason.

But when they play Friday night at HP Pavilion, the Sharks and Blackhawks will be just a couple of scuffling clubs badly in need of a win.

Chicago has slipped into a brutal tailspin. The Blackhawks arrive in town having lost six consecutive games and tumbling from their perch atop the Western Conference standings.

While the Blackhawks’ Zamboni has blown an engine, the Sharks merely are leaking oil. They have lost their last two games and continue to be plagued by inconsistent play. Regaining their edge against the Blackhawks would be a nice springboard for the upcoming nine-game road trip.

“The reality is every team is going to have ups and downs in a long season,” Sharks captain Joe Thornton said. “They’re hoping to get out of their funk, and so are we. But this is first time in a long while that both teams were struggling when we played each other. It’s definitely different.”

In fact, the Sharks and Blackhawks are examples of how quickly teams can find themselves mired in rough patches.

“Maybe we’re two wounded animals right now,” Sharks coach Todd McLellan said. “We’re not as deep into it as they are. But they’ll get themselves through this and be a force to be reckoned with. We just hope that it’s one night further down the line.”

Even the best franchises aren’t immune from skids. And the Blackhawks (29-18-7) should be very good.

They were leading the West thanks to a gifted offensive attack that overshadowed troubling cracks in the defense. But in the past six games, Chicago has scored more than two goals just once and has gone an ice-cold 1-for-15 on the power play.

That has put the focus on a struggling defense that is 26th in the NHL in goals allowed. Top blue-liners Duncan Keith and Brent Seabrook have played below their capabilities.

The Blackhawks also could finally be feeling the pain for letting current Sharks goaltender Antti Niemi walk before last season rather than pay him the $2.75 million he was awarded in arbitration. Corey Crawford, who will start Friday, and Ray Emery have a combined 2.91 goals-against average.

“It sucks,” Seabrook said of the slump. “Nobody wants to go through this. But it happens. We understand that we have to work hard to get out of it. It hurts to lose this many in a row. It’s definitely a pride issue. We need to start with one win.”

Chicago, which is in the middle of its own nine-game trip, also hasn’t won on the road since Dec. 14 — going 0-6-2. The low point was an 8-4 loss at Edmonton Feb. 2 when Sam Gagner ripped the Blackhawks for eight points.

“It’s definitely not fun,” forward Patrick Sharp said, “but we’re going to come out of this and be a better team for it.”

The Sharks, who are 4-5-1 over the last 10 games, have their own issues.

San Jose (29-16-6) has transformed itself into a more defensive-minded team this season. But the Sharks have turned in back-to-back ugly performances where giveaways and mental lapses contributed to nine goals.

Niemi wasn’t particularly sharp in either game, but he also has been getting little help from skaters in front of him. That’s why after practice Thursday, McLellan talked about the need for more consistent effort and better “commitment” in the defensive zone.

“We’re not built to give up four or five goals a game,” agreed forward Ryane Clowe. “We’ve got to tighten things up defensively. We’re not happy right now with the way we’re playing. This is a big game for us because we need a bounce with the road trip coming up.”

Around 5:35 p.m., CHP officers responded to a report of the incident in westbound I-580 lanes at Main Street. En route, officers learned a vehicle's driver said a person in another vehicle brandished a handgun and fired a shot.

In addition to evacuating 10 neighboring homes, deputies restricted pedestrian and vehicle traffic in the area while the sheriff's office bomb squad "safely disposed" of the explosives, officials said.